“There are a number of things in the legislation that are truly worrisome,” Kelsall said in an interview. “If the intent is truly a public health approach and to protect our youth this legislation is not doing it.”

Canadian youth ranked first for cannabis use in North America and Europe, with one-third saying they tried it at least once by age 15, the Canadian Pediatric Society says.

Before the federal election, physicians said the right legislation to legalize pot might curb teen toking by restricting access.

The editorial takes issue with several aspects of the bill, which:

Sets the minimum age to buy recreational marijuana at 18. Kelsall calls that too young given evidence suggesting that the human brain doesn’t mature until about age 25.

Allows people to grow pot at home, which Kelsall said increases the likelihood of diversion to young people.

Marijuana as a psychosis trigger

At the Centre for Addiction and Mental Health in Toronto, psychiatrist Romina Mizrah uses PET scanners to study how cannabis use changes brain function in young people with an average age of 20.

In young people who regularly use cannabis, preliminary evidence points to a reduction in an enzyme that regulates the endocannabinoid system that buffers key chemistry within the brain, said Mizrahi.

“There is some understanding at this point from epidemiological studies that certainly marijuana is a trigger,” said Mizrahi, director of the Focus on Youth Psychosis Prevention program. “Marijuana use predates the psychosis. Whether it causes the psychosis, that’s a different question and that we don’t know.”

More potent pot

Mike Stroh, 35, of Toronto says he’s part of a generation who grew up smoking current strains of marijuana, which have been genetically selected to produce a powerful high, with THC levels of about 20 per cent. That’s up from around seven per cent in the 1960s and ’70s.

From age 13, Stroh got high almost daily until age 30.

“I was into sports,” Stroh recalled. “I wanted to do stuff at school, but I wouldn’t make it to the practice, I wouldn’t make it to the tryouts, because I was either up all night selling drugs, trying to get them, fall asleep in a drug-induced coma, and then wake up in a mess.”

Mike Stroh started smoking pot almost daily from age 13 until he was 30. He says it’s an ‘illusion’ that pot is a relatively harmless drug. (CBC)

Stroh also lived with depression and anxiety and said he was never able to like himself. “That’s the torment that brought me to my knees.”

He felt robbed of being himself and the opportunity for emotional maturity, cognitive development and professional opportunities.

“Because marijuana doesn’t bring you to your knees as quickly as other drugs may … there’s this illusion that because you can be high and do things, it’s not bad, so to speak.”

Stroh is now a mental health advocate who draws on his personal and family experiences to educate.

“We need to teach kids how to take care of themselves so when they do feel anxious and do feel depressed, scared or … frustrated with life, because yes, that’s a part of being a teenager, then they learn that there’s so many things they can do to help themselves as opposed to use drugs.”